2015年河南两次东北冷涡型强对流天气对比分析  

Comparative analysis on two severe convective weather events associated with northeast cold vortex in Henan in 2015

作　　者：武威 牛淑贞 

机构地区：[1]河南省漯河市气象局,漯河462300 [2]河南省农业气象保障与应用技术重点实验室,郑州450003 [3]河南省气象台,郑州450003

出　　处：《暴雨灾害》2017年第5期397-409,共13页Torrential Rain and Disasters

基　　金：中国气象局气象关键技术集成与应用面上项目(CMAGJ2015M36);中国气象局预报员专项(CMAYBY2016-043);河南省预报员专项(KQ201741)

摘　　要：利用常规观测资料、NCEP 1°×1°间隔6 h再分析资料、区域加密站资料、卫星云图和雷达资料,对2015年5月6日(简称"05.06")和8月30日(简称"08.30")河南两次东北冷涡型强对流天气过程的系统配置、环境条件、中尺度特征等进行了详细分析。结果表明:(1)两次过程均发生在东北冷涡稳定维持下的环流背景下,"05.06"过程是在高层西北气流下由干冷平流强迫引起的大风冰雹伴随短时强降水的混合对流,"08.30"过程则由横槽南下及暖湿气流引起以短时强降水为主伴有大风的湿对流。(2)"05.06"过程中高层有较强的干冷平流,叠加在低层暖湿平流上,形成了强对流不稳定层结,强的垂直风切变位于中低层,配合较强的动力抬升条件,有利于冰雹发生发展;"08.30"过程则类似准正压类强对流,弱暖平流抬升配合上层冷平流形成不稳定,垂直风切变小,湿层较厚,有利于短时强降水的发生。(3)两次过程均发生在地面温度、露点大值区及高梯度区,高温高湿为其提供了能量和水汽条件,地面辐合线是其触发抬升机制。"05.06"过程冷暖交汇明显,干湿对比显著,是在冷暖交汇和干湿交汇共同有利环境下产生大风冰雹天气;"08.30"过程则是在高湿区中由冷暖交汇产生对流不稳定,以短时强降水为主。(4)两次过程均由发展旺盛的中β尺度对流云团自北向南移动产生,云顶TBB较低,中尺度雨团与TBB高梯度区对应较好。(5)雷达回波上,强对流过程中对流单体出现明显的回波悬垂、弱回波区以及有界弱回波等特征,径向速度场上有低层辐合和高层辐散、中层径向辐合、逆风区、中气旋等特征。Based on the conventionally observed data, NCEP 1°×1° 6 hourly reanalyzed data, intensive weather station data, satellite cloud images and radar data, the weather systems, their environmental conditions and mesoscale characteristics of two severe convective weather events associated with northeast cold vortex in Henan on 6 May('05.06'called for short) and 30 August('08.30'called for short) in 2015 were analyzed in detail. The results show that(1) two events occurred in the circulation background of northeast cold vortex. The'05.06'was a mixed convection event that has strong wind and hail with short heavy rainfall caused by dry and cold advections in the high-level. The'08.30'was a moist convection event that was mainly heavy rainfall with local wind caused by the warm and humid air mass and horizontal groove.(2) For the'05.06'event, the abundant moisture in the low-level with certain dynamic lifting and vertical wind shear conditions were conducive to the formation and development of severe weather. Strong cold advection appears in the middle-high levels stacking on the warm advection in the low-level, forming a strong unstable stratification. Strong vertical wind shear located in the middle and low levels, together with a certain power uplift conditions, was conducive to the occurrence and development of hail. The'08.30'event is similar to the convection of the quasi-positive pressure. Weak warm advection uplift together with the upper cold advection formed instability. The weak vertical wind shear and thick wet layer were conducive to short-term heavy rainfall.(3) The two events occurred in an area of high gradient region of temperature and dew point. High temperature and humidity provided unstable energy and high moisture conditions. Surface convergence line was not only the trigger of convective systems, but also the organizer of strong convective weather. Both were interdependent and mutually reinforcing. In'05.06'event, the intersection of cold and warm was clear and the contrast of dry and wet was sign

关 键 词：强对流天气 中尺度分析 短时强降水 东北冷涡 地面辐合线 

分 类 号：P458[天文地球—大气科学及气象学]